1. Technical Field.
This invention relates generally to recreational vehicle waste discharge flexible pipe adapters, and it more particularly relates to an adapter for coupling in fluid communication a flexible corrugated drainpipe and a recreational vehicle discharge pipe fitting.
2. Background Art.
Connecting drainpipe to a conventional recreational vehicle discharge pipe fitting does requires considerable unwanted and undesirable effort. Commonly employed flexible drainpipe includes a coiled spring imbedded within a plastic casing, which follows the helical outline of the coiled spring to cause the drainpipe to assume a corrugated shape. Such a drainpipe can have a diameter of approximately three inches, to provide adequate drainage under the flow of gravity, for most recreational vehicle requirements.
The recreational vehicle discharge pipe typically terminates at an outlet end at the exterior of the vehicle. The outlet end includes a discharge pipe fitting to which the drainpipe is coupled in fluid communication. The coupling of a drainpipe to the discharge pipe fitting is often accomplished by forcing the drainpipe onto or into the outlet end of the discharge pipe by extremely awkward manual manipulations, since the end of the discharge pipe is not constructed to receive the end of the commonly-used flexible drainpipe.
A very novel discharge pipe adapter that overcomes many of these problems is described in the foregoing copending patent application Ser. No. 855,924. The adapter employs a tubular member having a helically-shaped thread extending along one end for fast threadable engagement with the corrugations of corrugated drainpipe. The opposite end includes a plurality of spaced, open angular slots which receive a pair outwardly radially projecting pins on the discharge pipe fitting, to enable quick release or assembly in a latched manner onto and off to the end of the discharge pipe.
Although such adapter is highly effective and satisfactory in many respects, in some applications, such adapter may not securely assemble to the pipe fitting. For example, the pins on different discharge pipe fittings are often in different locations on the outlet end of the discharge pipe. In addition, the pins are oftentimes slightly misaligned, varying somewhat in their position relative to the terminal end of the fitting. This inhibits positive engagement with each one of the pins within the corresponding angular slots of the adapter. Furthermore, the smooth plastic composition employed in such an adapter, increases the tendency for dislodgement, so that joint integrity may be jeopardized in certain situations.
Consequently, it is desirable to have a new and improved adapter, which overcomes the problem of less than a secure engagement of the discharge pipe fitting with the adapter in certain applications.
A related problem concerns the sealing of the adapter to the terminal end of the discharge pipe fitting. Existing adapters often result in an inadequate seal so that waste can leak from the adapter at a location close to the recreational vehicle. Consequently, it is desirable to have an adapter, which provides better sealing engagement with the discharge pipe fitting.
In addition, it is desirable to have an adapter, which is easily gripped, so that it can be threadably onto the corrugated drain pipe, conveniently by hand, as well as being inexpensive to manufacture.
There have been many different types and kinds of couplers and adapters designed for similar purposes. Refer, for example, to U.S. Pat. Nos. 3,408,091; 3,471,179; 3,493,251; 3,899,198; 4,017,103; 4,133,347; 4,222,594; 4,368,904; 4,480,855; and 4,542,922. However, none of the foregoing patents disclose devices capable of adequately solving the aforementioned problems.